use strict; use warnings; my @files = qw( 9.10.force.0.5.1LGY.pdb 29.30.force.0.5.1LGY.pdb 30.31.force.0.5.1LGY.pdb 31.32.force.0.5.1LGY.pdb 100.101.force.0.5.1LGY.pdb 101.102.force.0.5.1LGY.pdb ); my @sorted = map { $_->[0] } sort { $a->[1] <=> $b->[1] } map { [ $_, split( /\./, $_ ) ] } @files; print "$_\n" for @sorted;